Impact Bit Holder with Knurled Grip for 1/4" (6.3) Hex Bits. Input Drive Size: 3/8" Drive Shape: Square Length: 42mm Type: Impact Bit Holder for 1/4" (6.3) Bits Output Size: 1/4" Opening: Hex Product Dimension (Refer Line Drawing Image): D1 Size: 13mm D2 Size: 19mm L Size: 42mm 3/8 Sq. Dr. Impact Bit Holder for 1/4 (6.3) Hex Bits - Length 42mm